The New York Times is reporting that even as thousands of ballots from New York City's mayoral primary had yet to be counted on Thursday, Democrats and Republicans began to square off, highlighting the deep ideological divide of a general-election matchup.

Campaigning for the first time since securing the Republican nomination, [Joseph L.] Lhota promised "a takedown" of his likely Democratic opponent, accusing [Bill] de Blasio of dividing New Yorkers with his populist "tale of two cities" message and of promoting " a repudiation of everything great that's happened over the last 20 years."

It did not take long for Mr. de Blasio to fire back. Speaking at a campaign rally with labor supporters in Brooklyn, he said his critics had failed to address the most serious economic issues facing the city.

"Acceptance of inequality, turning the other way when there's inequality, that's not an American value, and that's not the values of the city of New York," Mr. de Blasio said to cheers.